How to get high quality alloy steel pipes?

Alloy steel pipes are hollow pipe with round cross section for the conveyance of products. The products include fluids, gas, pellets, powders and more. The word pipe is used as distinguished from tube to apply to tubular products of dimensions commonly used for pipeline and piping systems.

Strictly speaking, every steel is an alloy, but not all steels are called “alloy steels”. The simplest steels areiron (Fe) alloyed with carbon (C) (about 0.1% to 1%, depending on type). However, the term “alloy steel” is the standard term referring to steels with other alloying elements added deliberately in addition to the carbon. Common alloyants include manganese (the most common one), nickel, chromium, molybdenum, vanadium, silicon, and boron. Less common alloyants include aluminum, cobalt, copper, cerium, niobium, titanium, tungsten, tin, zinc, lead, andzirconium.The following is a range of improved properties in alloy steels (as compared to carbon steels): strength, hardness,toughness, wear resistance, corrosion resistance, hardenability, and hot hardness. To achieve some of these improved properties the metal may require heat treating.Some of these find uses in exotic and highly-demanding applications, such as in the turbine blades of jet engines, in spacecraft, and in nuclear reactors. Because of the ferromagnetic properties of iron, some steel alloys find important applications where their responses to magnetism are very important, including in electric motors and intransformers.

Alloy steel pipe is a kind of seamless steel pipe, its performance is much higher than the general seamless steel pipe, because this steel pipe inside containing Cr, high temperature resistance, low temperature, corrosion-resistant performance of other non-pipe joints not match, so the more extensive use of alloy steel pipe in the petroleum, aerospace, chemical, electric power, boiler, military, and other industries.The main use of alloy steel pipe used in power plants, nuclear power, high-pressure boiler, high temperature superheater and re-heater high pressure and high temperature piping and equipment, it is made of high quality carbon steel, alloy structural steel and heat-resistant stainless steel material, hot-rolled (extrusion, expansion) or cold-rolled (pull) made.

How to get high quality alloy steel pipes?

The biggest advantages of alloy steel pipeCan be 100% recycled, environmentally friendly, energy-saving, resource conservation, national strategy, national policy to encourage the expansion of the field of application of high-pressure alloy pipe. Of alloy steel pipe total consumption accounted steel in the proportion is only half of the developed countries, to expand the field of use of the alloy steel pipe to provide a wider space for the development of the industry. The future needs of the average annual growth of China’s high-pressure alloy steel pipe long products up to 10-12%.

Specification, Standard and identification of alloy steel pipes

Alloy Steel pipe contains substantial quantities of elements other than carbon such as nickel, chromium, silicon, manganese, tungsten, molybdenum, vanadium and limited amounts of other commonly accepted elements such as manganese, sulfur, silicon, and phosphorous.

ASTM A335 Pipe Specifications

ASTM A335 standard is issued under the fixed designation A 335/A 335M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon ( ュ) indicates an editorial change since the last revision or reapproval.

ASTM A333 Pipe Specifications

ASTM A333 is the Standard Specification for Seamless and Welded Steel Pipe for Low-Temperature Service.

ASTM A333 alloy steel pipe shall be made by the seamless or welding process with the addition of no filler metal in the welding operation. All seamless and welded pipes shall be treated to control their microstructure.

ASTM A213M-09 Standard Specication

ASTM A213M-09 standard is issued under the fixed designation A 213/A 213M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision.

ASTM A519-89 Standard specification

ASTM A519- specification covers for several grades of carbon and alloy steel mechanical tubing, either hot-finished or cold-finished.

The steel used in the mechanical tubing may be cast in ingots or may be strand cast. When steel of different grades is sequentially strand cast, identification of the resultant transition material is required.

The Advantages Of Alloy Steel Pipe

The main applications of alloy steel pipe is power station, nuclear power plant, high pressure boiler, high temperature superheater and re-heater coil etc. of high temperature pipeline and equipments.

The advantages of alloy steel pipe: 100% recycled, it is suitable for the national strategy of environmental protection, energy-saving and resource-saving. Therefore, the national policy encourages the expansion of the high pressure alloy steel pipe applications.

At present, the proportion of the total alloy steel tube is half of the developed countries. The applications of alloy steel pipe provide a broad space for the industry development. According to the research of the China association of special steel alloy pipe expert group, our country’s high pressure alloy steel pipe material demand grows by an average of up to 10-12%.

There are three processes for metallic pipe manufacture. Centrifugal casting of hot alloyed metal is one of the most prominent process.[citation needed] Ductile iron pipes are generally manufactured in such a fashion. Seamless (SMLS) pipe is formed by drawing a solid billet over a piercing rod to create the hollow shell. As the manufacturing process does not include any welding, seamless pipes are perceived to be stronger and more reliable. Historically, seamless pipe was regarded as withstanding pressure better than other types, and was often more available than welded pipe.

Advances since the 1970s in materials, process control, and non-destructive testing, allow correctly specified welded pipe to replace seamless in many applications. Welded pipe is formed by rolling plate and welding the seam (usually by Electric resistance welding (“ERW”), or Electric Fusion Welding (“EFW”)). The weld flash can be removed from both inner and outer surfaces using a scarfing blade. The weld zone can also be heat-treated to make the seam less visible. Welded pipe often have tighter dimensional tolerances than the seamless type, and can be cheaper to manufacture.

There are a number of processes that may be used to produce ERW pipes. Each of these processes leads to coalescence or merging of steel components into pipes. Electric current is passed through the surfaces that have to be welded together; as the components being welded together resist the electric current, heat is generated which forms the weld. Pools of molten metal are formed where the two surfaces are connected as a strong electric current is passed through the metal; these pools of molten metal form the weld that binds the two abutted components.

ERW pipes are manufactured from the longitudinal welding of steel. The welding process for ERW pipes is continuous, as opposed to welding of distinct sections at intervals. ERW process uses steel coil as feedstock.

The High Frequency Induction Technology (HFI) welding process is used for manufacturing ERW pipes. In this process, the current to weld the pipe is applied by means of an induction coil around the tube. HFI is generally considered to be technically superior to “ordinary” ERW when manufacturing pipes for critical applications, such as for usage in the energy sector, in addition to other uses in line pipe applications, as well as for casing and tubing.

Large-diameter pipe (25 centimetres (10 in) or greater) may be ERW, EFW or Submerged Arc Welded (“SAW”) pipe. There are two technologies that can be used to manufacture steel pipes of sizes larger than the steel pipes that can be produced by seamless and ERW processes. The two types of pipes produced through these technologies are longitudinal-submerged arc-welded (LSAW) and spiral-submerged arc-welded (SSAW) pipes. LSAW are made by bending and welding wide steel plates and most commonly used in oil and gas industry applications. Due to their high cost, LSAW pipes are seldom used in lower value non-energy applications such as water pipelines. SSAW pipes are produced by spiral (helicoidal) welding of steel coil and have a cost advantage over LSAW pipes, as the process uses coils rather than steel plates. As such, in applications where spiral-weld is acceptable, SSAW pipes may be preferred over LSAW pipes. Both LSAW pipes and SSAW pipes compete against ERW pipes and seamless pipes in the diameter ranges of 16”-24”.